Meeting requests don't appear in Manager's calendar if delegate is logged out

Exchange 2010 SP2 RU4

Outlook 2010

Both users have Outlook 2010.

When meeting requests are sent to the manager, everything is fine as long as the delegate has Outlook running.

If she closes out, the meetings don't appear in the manager's calendar at all.

I have recreated the delegate's .ost; used the cleanreminders switch to open her Outlook, etc.

I won't have access to the manager's machine until tomorrow.

I'm hoping for some pointers on what to look for and where to start.

Thanks all!